1/*
2 * Wireless Host Controller (WHC) periodic schedule management.
3 *
4 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17 */
18#include <linux/kernel.h>
19#include <linux/gfp.h>
20#include <linux/dma-mapping.h>
21#include <linux/uwb/umc.h>
22#include <linux/usb.h>
23
24#include "../../wusbcore/wusbhc.h"
25
26#include "whcd.h"
27
28static void update_pzl_pointers(struct whc *whc, int period, u64 addr)
29{
30	switch (period) {
31	case 0:
32		whc_qset_set_link_ptr(&whc->pz_list[0], addr);
33		whc_qset_set_link_ptr(&whc->pz_list[2], addr);
34		whc_qset_set_link_ptr(&whc->pz_list[4], addr);
35		whc_qset_set_link_ptr(&whc->pz_list[6], addr);
36		whc_qset_set_link_ptr(&whc->pz_list[8], addr);
37		whc_qset_set_link_ptr(&whc->pz_list[10], addr);
38		whc_qset_set_link_ptr(&whc->pz_list[12], addr);
39		whc_qset_set_link_ptr(&whc->pz_list[14], addr);
40		break;
41	case 1:
42		whc_qset_set_link_ptr(&whc->pz_list[1], addr);
43		whc_qset_set_link_ptr(&whc->pz_list[5], addr);
44		whc_qset_set_link_ptr(&whc->pz_list[9], addr);
45		whc_qset_set_link_ptr(&whc->pz_list[13], addr);
46		break;
47	case 2:
48		whc_qset_set_link_ptr(&whc->pz_list[3], addr);
49		whc_qset_set_link_ptr(&whc->pz_list[11], addr);
50		break;
51	case 3:
52		whc_qset_set_link_ptr(&whc->pz_list[7], addr);
53		break;
54	case 4:
55		whc_qset_set_link_ptr(&whc->pz_list[15], addr);
56		break;
57	}
58}
59
60/*
61 * Return the 'period' to use for this qset.  The minimum interval for
62 * the endpoint is used so whatever urbs are submitted the device is
63 * polled often enough.
64 */
65static int qset_get_period(struct whc *whc, struct whc_qset *qset)
66{
67	uint8_t bInterval = qset->ep->desc.bInterval;
68
69	if (bInterval < 6)
70		bInterval = 6;
71	if (bInterval > 10)
72		bInterval = 10;
73	return bInterval - 6;
74}
75
76static void qset_insert_in_sw_list(struct whc *whc, struct whc_qset *qset)
77{
78	int period;
79
80	period = qset_get_period(whc, qset);
81
82	qset_clear(whc, qset);
83	list_move(&qset->list_node, &whc->periodic_list[period]);
84	qset->in_sw_list = true;
85}
86
87static void pzl_qset_remove(struct whc *whc, struct whc_qset *qset)
88{
89	list_move(&qset->list_node, &whc->periodic_removed_list);
90	qset->in_hw_list = false;
91	qset->in_sw_list = false;
92}
93
94/**
95 * pzl_process_qset - process any recently inactivated or halted qTDs
96 * in a qset.
97 *
98 * After inactive qTDs are removed, new qTDs can be added if the
99 * urb queue still contains URBs.
100 *
101 * Returns the schedule updates required.
102 */
103static enum whc_update pzl_process_qset(struct whc *whc, struct whc_qset *qset)
104{
105	enum whc_update update = 0;
106	uint32_t status = 0;
107
108	while (qset->ntds) {
109		struct whc_qtd *td;
110		int t;
111
112		t = qset->td_start;
113		td = &qset->qtd[qset->td_start];
114		status = le32_to_cpu(td->status);
115
116		/*
117		 * Nothing to do with a still active qTD.
118		 */
119		if (status & QTD_STS_ACTIVE)
120			break;
121
122		if (status & QTD_STS_HALTED) {
123			/* Ug, an error. */
124			process_halted_qtd(whc, qset, td);
125			/* A halted qTD always triggers an update
126			   because the qset was either removed or
127			   reactivated. */
128			update |= WHC_UPDATE_UPDATED;
129			goto done;
130		}
131
132		/* Mmm, a completed qTD. */
133		process_inactive_qtd(whc, qset, td);
134	}
135
136	if (!qset->remove)
137		update |= qset_add_qtds(whc, qset);
138
139done:
140	/*
141	 * If there are no qTDs in this qset, remove it from the PZL.
142	 */
143	if (qset->remove && qset->ntds == 0) {
144		pzl_qset_remove(whc, qset);
145		update |= WHC_UPDATE_REMOVED;
146	}
147
148	return update;
149}
150
151/**
152 * pzl_start - start the periodic schedule
153 * @whc: the WHCI host controller
154 *
155 * The PZL must be valid (e.g., all entries in the list should have
156 * the T bit set).
157 */
158void pzl_start(struct whc *whc)
159{
160	le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
161
162	whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, WUSBCMD_PERIODIC_EN);
163	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
164		      WUSBSTS_PERIODIC_SCHED, WUSBSTS_PERIODIC_SCHED,
165		      1000, "start PZL");
166}
167
168/**
169 * pzl_stop - stop the periodic schedule
170 * @whc: the WHCI host controller
171 */
172void pzl_stop(struct whc *whc)
173{
174	whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, 0);
175	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
176		      WUSBSTS_PERIODIC_SCHED, 0,
177		      1000, "stop PZL");
178}
179
180/**
181 * pzl_update - request a PZL update and wait for the hardware to be synced
182 * @whc: the WHCI HC
183 * @wusbcmd: WUSBCMD value to start the update.
184 *
185 * If the WUSB HC is inactive (i.e., the PZL is stopped) then the
186 * update must be skipped as the hardware may not respond to update
187 * requests.
188 */
189void pzl_update(struct whc *whc, uint32_t wusbcmd)
190{
191	struct wusbhc *wusbhc = &whc->wusbhc;
192	long t;
193
194	mutex_lock(&wusbhc->mutex);
195	if (wusbhc->active) {
196		whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
197		t = wait_event_timeout(
198			whc->periodic_list_wq,
199			(le_readl(whc->base + WUSBCMD) & WUSBCMD_PERIODIC_UPDATED) == 0,
200			msecs_to_jiffies(1000));
201		if (t == 0)
202			whc_hw_error(whc, "PZL update timeout");
203	}
204	mutex_unlock(&wusbhc->mutex);
205}
206
207static void update_pzl_hw_view(struct whc *whc)
208{
209	struct whc_qset *qset, *t;
210	int period;
211	u64 tmp_qh = 0;
212
213	for (period = 0; period < 5; period++) {
214		list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
215			whc_qset_set_link_ptr(&qset->qh.link, tmp_qh);
216			tmp_qh = qset->qset_dma;
217			qset->in_hw_list = true;
218		}
219		update_pzl_pointers(whc, period, tmp_qh);
220	}
221}
222
223/**
224 * scan_periodic_work - scan the PZL for qsets to process.
225 *
226 * Process each qset in the PZL in turn and then signal the WHC that
227 * the PZL has been updated.
228 *
229 * Then start, stop or update the periodic schedule as required.
230 */
231void scan_periodic_work(struct work_struct *work)
232{
233	struct whc *whc = container_of(work, struct whc, periodic_work);
234	struct whc_qset *qset, *t;
235	enum whc_update update = 0;
236	int period;
237
238	spin_lock_irq(&whc->lock);
239
240	for (period = 4; period >= 0; period--) {
241		list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
242			if (!qset->in_hw_list)
243				update |= WHC_UPDATE_ADDED;
244			update |= pzl_process_qset(whc, qset);
245		}
246	}
247
248	if (update & (WHC_UPDATE_ADDED | WHC_UPDATE_REMOVED))
249		update_pzl_hw_view(whc);
250
251	spin_unlock_irq(&whc->lock);
252
253	if (update) {
254		uint32_t wusbcmd = WUSBCMD_PERIODIC_UPDATED | WUSBCMD_PERIODIC_SYNCED_DB;
255		if (update & WHC_UPDATE_REMOVED)
256			wusbcmd |= WUSBCMD_PERIODIC_QSET_RM;
257		pzl_update(whc, wusbcmd);
258	}
259
260	/*
261	 * Now that the PZL is updated, complete the removal of any
262	 * removed qsets.
263	 *
264	 * If the qset was to be reset, do so and reinsert it into the
265	 * PZL if it has pending transfers.
266	 */
267	spin_lock_irq(&whc->lock);
268
269	list_for_each_entry_safe(qset, t, &whc->periodic_removed_list, list_node) {
270		qset_remove_complete(whc, qset);
271		if (qset->reset) {
272			qset_reset(whc, qset);
273			if (!list_empty(&qset->stds)) {
274				qset_insert_in_sw_list(whc, qset);
275				queue_work(whc->workqueue, &whc->periodic_work);
276			}
277		}
278	}
279
280	spin_unlock_irq(&whc->lock);
281}
282
283/**
284 * pzl_urb_enqueue - queue an URB onto the periodic list (PZL)
285 * @whc: the WHCI host controller
286 * @urb: the URB to enqueue
287 * @mem_flags: flags for any memory allocations
288 *
289 * The qset for the endpoint is obtained and the urb queued on to it.
290 *
291 * Work is scheduled to update the hardware's view of the PZL.
292 */
293int pzl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
294{
295	struct whc_qset *qset;
296	int err;
297	unsigned long flags;
298
299	spin_lock_irqsave(&whc->lock, flags);
300
301	err = usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
302	if (err < 0) {
303		spin_unlock_irqrestore(&whc->lock, flags);
304		return err;
305	}
306
307	qset = get_qset(whc, urb, GFP_ATOMIC);
308	if (qset == NULL)
309		err = -ENOMEM;
310	else
311		err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
312	if (!err) {
313		if (!qset->in_sw_list && !qset->remove)
314			qset_insert_in_sw_list(whc, qset);
315	} else
316		usb_hcd_unlink_urb_from_ep(&whc->wusbhc.usb_hcd, urb);
317
318	spin_unlock_irqrestore(&whc->lock, flags);
319
320	if (!err)
321		queue_work(whc->workqueue, &whc->periodic_work);
322
323	return err;
324}
325
326/**
327 * pzl_urb_dequeue - remove an URB (qset) from the periodic list
328 * @whc: the WHCI host controller
329 * @urb: the URB to dequeue
330 * @status: the current status of the URB
331 *
332 * URBs that do yet have qTDs can simply be removed from the software
333 * queue, otherwise the qset must be removed so the qTDs can be safely
334 * removed.
335 */
336int pzl_urb_dequeue(struct whc *whc, struct urb *urb, int status)
337{
338	struct whc_urb *wurb = urb->hcpriv;
339	struct whc_qset *qset = wurb->qset;
340	struct whc_std *std, *t;
341	bool has_qtd = false;
342	int ret;
343	unsigned long flags;
344
345	spin_lock_irqsave(&whc->lock, flags);
346
347	ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
348	if (ret < 0)
349		goto out;
350
351	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
352		if (std->urb == urb) {
353			if (std->qtd)
354				has_qtd = true;
355			qset_free_std(whc, std);
356		} else
357			std->qtd = NULL; /* so this std is re-added when the qset is */
358	}
359
360	if (has_qtd) {
361		pzl_qset_remove(whc, qset);
362		update_pzl_hw_view(whc);
363		wurb->status = status;
364		wurb->is_async = false;
365		queue_work(whc->workqueue, &wurb->dequeue_work);
366	} else
367		qset_remove_urb(whc, qset, urb, status);
368out:
369	spin_unlock_irqrestore(&whc->lock, flags);
370
371	return ret;
372}
373
374/**
375 * pzl_qset_delete - delete a qset from the PZL
376 */
377void pzl_qset_delete(struct whc *whc, struct whc_qset *qset)
378{
379	qset->remove = 1;
380	queue_work(whc->workqueue, &whc->periodic_work);
381	qset_delete(whc, qset);
382}
383
384/**
385 * pzl_init - initialize the periodic zone list
386 * @whc: the WHCI host controller
387 */
388int pzl_init(struct whc *whc)
389{
390	int i;
391
392	whc->pz_list = dma_alloc_coherent(&whc->umc->dev, sizeof(u64) * 16,
393					  &whc->pz_list_dma, GFP_KERNEL);
394	if (whc->pz_list == NULL)
395		return -ENOMEM;
396
397	/* Set T bit on all elements in PZL. */
398	for (i = 0; i < 16; i++)
399		whc->pz_list[i] = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);
400
401	le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
402
403	return 0;
404}
405
406/**
407 * pzl_clean_up - free PZL resources
408 * @whc: the WHCI host controller
409 *
410 * The PZL is stopped and empty.
411 */
412void pzl_clean_up(struct whc *whc)
413{
414	if (whc->pz_list)
415		dma_free_coherent(&whc->umc->dev,  sizeof(u64) * 16, whc->pz_list,
416				  whc->pz_list_dma);
417}
418